Power supply



FIG. 1 is a perspective view of a power supply showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a second perspective view showing the power supply.

The broken lines shown represent unclaimed subject matter and form no part of the claimed design. 

CLAIM The ornamental design for a power supply, as shown and described. 